1. Technical Field
The disclosure relates to a hybrid vehicle, and relates also to a method of controlling the hybrid vehicle.
2. Description of Related Art
Japanese Unexamined Patent Application Publication No. 2013-252853 (JP 2013-252853 A) describes a hybrid vehicle including a power generation apparatus that includes an electric motor and an engine provided with an exhaust gas catalyst, and an electricity storage device configured to supply electricity to the electric motor or to be supplied with electricity from the electric motor. In the hybrid vehicle described in JP 2013-252853 A, either a charge-depleting (CD) mode or a charge-sustaining (CS) mode can be set as a traveling mode of the hybrid vehicle. In the hybrid vehicle described in JP 2013-252853 A, while the traveling mode is the CD mode, a higher priority is given to electric traveling (EV traveling) in which only the electric motor is used as a power source to promote consumption of electricity stored in the electricity storage device, while hybrid traveling (HV traveling) accompanied by an operation of the engine is also permitted. On the other hand, while the traveling mode of the hybrid vehicle is the CS mode, switching between HV traveling and EV traveling is performed as needed, to maintain the state-of-charge (SOC) of the electricity storage device within a prescribed range.
As this kind of hybrid vehicle, Japanese Unexamined Patent Application Publication 2013-154715 (JP 2013-154715 A) describes a hybrid vehicle provided with a switch for performing switching from an EV (CD) mode where the hybrid vehicle travels using only an electric motor as a power source without using an engine as a power source, to an HV (CS) mode where the hybrid vehicle travels using both the engine and the electric motor as power sources. While the hybrid vehicle according to JP 2013-154715 A is traveling in the HV mode after a driver manually switches the traveling mode from the EV mode to the HV mode, an SOC control center value, which is a control target value of the state-of-charge (SOC) of an electricity storage device, is set to a value higher than the SOC of the electricity storage device at the time when the hybrid vehicle is traveling in the EV mode immediately before the traveling mode is switched to the HV mode. Thus, the SOC of the electricity storage device at the time when the driver manually switches the traveling mode from the EV mode to the HV mode can be maintained while the hybrid vehicle is traveling in the HV mode after the traveling mode is switched to the HV mode. JP 2013-154715 A further describes that, while the hybrid vehicle is traveling in the HV mode after the driver manually switches the traveling mode from the EV mode to the HV mode, the SOC of the electricity storage device at the time when the traveling mode is switched from the EV mode to the HV mode, is set as the SOC control center value.